Diamond is an extraordinary material which has, among other characteristics, superlative hardness, thermal conductivity, and optical transmissivity. It is also an excellent electrical insulator and chemically inert in most environments. In recent years, techniques have been devised for fabricating relatively large pieces of synthetic diamond, such as by chemical vapor deposition ("CVD") methods. When, for example, a relatively large wafer of synthetic diamond is made, it may be desirable to cut or dice the wafer into smaller pieces for uses such as optical windows, electronic substrates, or heat sinks. Since diamond is the hardest known material, it is very difficult to cut. Cutting with another diamond medium can be a slow and expensive process. Wire electro discharge machining ("wire EDM") is not suitable for cutting high quality diamond, because the electrical conductivity is too low. Laser cutting can be employed for some applications, but the focused laser beam typically used for cutting has a conical shape that is of limited utility for cutting materials of substantial thickness, since the cut becomes relatively wide and tends to consume too much diamond.
The general inertness of diamond renders chemically based cutting difficult. Use of a wheel made from a metal that reacts with diamond has had limited success.
It is among the objects of the present invention to provide a technique and apparatus for cutting diamond, and to overcome limitations of prior art techniques.